Millimeter to Ken Converter
Convert millimeters to ken with our free online length converter.
Quick Answer
1 Millimeter = 0.00055 ken
Formula: Millimeter Γ conversion factor = Ken
Use the calculator below for instant, accurate conversions.
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All conversion formulas on UnitsConverter.io have been verified against NIST (National Institute of Standards and Technology) guidelines and international SI standards. Our calculations are accurate to 10 decimal places for standard conversions and use arbitrary precision arithmetic for astronomical units.
Millimeter to Ken Calculator
How to Use the Millimeter to Ken Calculator:
- Enter the value you want to convert in the 'From' field (Millimeter).
- The converted value in Ken will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Length category.
- Click the swap button (β) to reverse the conversion direction.
How to Convert Millimeter to Ken: Step-by-Step Guide
Converting Millimeter to Ken involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Millimeter = 0.000550055 kenExample Calculation:
Convert 10 millimeters: 10 Γ 0.000550055 = 0.00550055 ken
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.
Need to convert to other length units?
View all Length conversions βWhat is a Millimeter and a Ken?
The millimeter (symbol: mm) is a unit of length in the metric system equal to one-thousandth of a meter (1/1,000 m) or one-tenth of a centimeter (1/10 cm). It is used for precise measurements in engineering, manufacturing, and everyday applications.
Key relationships:
- 1 millimeter = 0.001 meters (m)
- 1 millimeter = 0.1 centimeters (cm)
- 10 millimeters = 1 centimeter
- 1,000 millimeters = 1 meter
- 1 millimeter β 0.03937 inches (about 1/25th inch)
- 25.4 millimeters = 1 inch (exactly)
The prefix "milli-":
- From Latin "mille" meaning "thousand"
- SI prefix denoting 10β»Β³ (one-thousandth)
- Also used in: milligram (mg), milliliter (mL), millisecond (ms)
Visual perspective (how big is it?):
- 1 mm = Thickness of a credit card
- 2 mm = Thickness of a US dime
- 5 mm = Thickness of a pencil lead (mechanical)
- 10 mm = Width of an adult fingernail
- 25.4 mm = Exactly one inch
Convert between length units: mm converter
The Ken (ι) is a traditional Japanese unit of length, primarily used in architecture and related fields. It is fundamentally defined as being equal to 6 Shaku (ε°Ί). Based on the modern standardized kanejaku Shaku (10/33 meters), the Ken is equivalent to:
- 6 * (10/33) = 60/33 = 20/11 meters
- Approximately 1.818 meters
- Approximately 5.965 feet
Historically, the Ken represented the interval between pillars in traditional Japanese buildings and served as a fundamental module for architectural design, influencing room sizes and the dimensions of elements like tatami mats.
Note: The Millimeter is part of the metric (SI) system, primarily used globally in science and trade. The Ken belongs to the imperial/US customary system.
History of the Millimeter and Ken
-
Metric System Origins: The millimeter was defined as a subunit of the meter when the metric system was established in France during the late 18th century (1790s). As measurement standardization progressed, the need for decimal subdivisions of the meter became clear.
-
Industrial Revolution: The millimeter became essential during the 19th century Industrial Revolution as:
- Precision machining required fine tolerances
- Interchangeable parts manufacturing emerged
- Engineering drawings needed standard units
- Technical specifications became international
-
Engineering Adoption: By the mid-19th century, engineers and machinists worldwide adopted millimeters as the standard for:
- Machine tool specifications
- Tolerance requirements (Β±0.1 mm common)
- Technical drawing dimensions
- Quality control measurements
-
Scientific Standardization: The millimeter became standard in scientific research for:
- Laboratory equipment calibration
- Microscopy measurements
- Specimen documentation
- Experimental apparatus dimensions
-
SI Formalization: When the International System of Units (SI) was established in 1960, the millimeter was confirmed as an official subdivision of the meter, forming part of the coherent decimal system.
-
Modern Manufacturing: The 20th century saw millimeters become universal in:
- Automotive engineering specifications
- Electronics manufacturing (PCB design)
- Aerospace tolerances
- Medical device specifications
- Consumer product dimensions
-
Global Standard: Today, millimeters are the primary unit for precision measurements in virtually every country except the United States (which uses both mm and inches). Even in the US, many technical fields have adopted millimeters as standard.
The concept of the Ken, like the Shaku, originated from Chinese architectural practices (where the equivalent unit is Jian ι). It was adopted into Japan along with other elements of Chinese culture and measurement systems.
- Early Use: The Ken was used early on as a standard interval in temple and palace construction. Its length, however, was not strictly fixed and could vary based on the specific building style, region, or period. It was often tied directly to the prevailing length of the Shaku.
- Standardization Attempts: Over time, particularly during the Edo period (1603β1868), attempts were made to standardize measurements. The Ken became strongly associated with architectural modules. Two prominent regional standards emerged:
- KyΕma (δΊ¬ι): The Kyoto module, typically based on a slightly larger Ken (often around 6.5 Shaku or based on tatami dimensions), leading to larger room sizes.
- Inakama (η°θι) / Edoma (ζ±ζΈι): The rural or Edo (Tokyo) module, typically adhering more closely to the 6 Shaku standard or sometimes slightly smaller (e.g., 6.3 Shaku), resulting in slightly smaller rooms. This became more common.
- Meiji Restoration (1868 onwards): With the standardization of the Shaku at 10/33 meters in 1891, the Ken was implicitly standardized as 6 Shaku = 20/11 meters (approx. 1.818 m). This is the value generally understood as the modern Ken.
- Metrication: Although Japan officially adopted the metric system, the Ken remains a crucial unit in traditional architecture and related fields.
Common Uses and Applications: millimeters vs ken
Explore the typical applications for both Millimeter (metric) and Ken (imperial/US) to understand their common contexts.
Common Uses for millimeters
The millimeter is the standard unit for precise measurements across multiple fields:
Engineering & Machining
Precise measurement requirements for manufacturing, quality control, and technical specifications. Essential for maintaining tolerances in mechanical parts.
Why millimeters in engineering:
- Decimal system (easy calculations)
- International standard (ISO)
- Suitable precision range
- Compatible with CNC machinery
- Standard drawing units
Applications:
- Machine tool specifications
- Part tolerances (Β±0.05 mm common)
- Technical drawing dimensions
- CAD/CAM software units
- Quality inspection reports
Convert for technical work: mm to inches | mm to cm
Technical Design & Drafting
Standard measurement unit for architectural, mechanical, and technical drawings worldwide.
Drawing Standards:
- ISO standards use millimeters
- Engineering drawings in mm
- Architecture plans (many countries)
- Product design specifications
- Patent drawings (international)
Why mm for drawings:
- Eliminates fractions (unlike inches)
- Scales easily (1:10, 1:100, etc.)
- International communication
- CAD software standard
Electronics & PCB Design
Measuring component sizes, trace widths, and circuit board dimensions in electronic manufacturing.
PCB Design:
- Trace width: 0.25-1 mm
- Component footprints: mm specifications
- Hole diameters: 0.6-1.2 mm
- Board thickness: 1.6 mm standard
- Component spacing: mm grid
Component Specs:
- All modern ICs specified in mm
- Resistor/capacitor sizes (mm codes)
- Connector dimensions
- Display module sizes
Meteorology & Climate
Measuring rainfall amounts with precision, essential for weather forecasting, agriculture, and climate research.
Rain Gauges:
- Standard measurement unit worldwide
- Collected in graduated cylinders (mm scale)
- Automated weather stations use mm
- Historical records in mm
- Climate data standardized
Importance:
- Drought assessment
- Flood prediction
- Agricultural planning
- Water resource management
- Climate change tracking
Use our mm converter for scientific calculations.
Manufacturing & Quality Control
Inspecting product dimensions and ensuring parts meet specifications within required tolerances.
QC Measurements:
- Caliper readings in mm
- Micrometer measurements
- Coordinate measuring machines (CMM)
- Surface profile measurements
- Dimensional inspection reports
Industries:
- Automotive parts
- Aerospace components
- Medical devices
- Consumer electronics
- Precision instruments
Jewelry & Watchmaking
Specifying sizes of gems, watch cases, and jewelry components with precision.
Why jewelers use mm:
- International gem standard
- Precise size communication
- Watch industry standard
- Setting specifications
- Customer communication
Measurements:
- Gemstone dimensions
- Ring widths and thicknesses
- Watch case diameters
- Bracelet link sizes
- Clasp dimensions
Medical Measurements
Documenting precise measurements in diagnostics, surgery planning, and treatment monitoring.
Clinical Uses:
- Imaging measurements (CT, MRI, X-ray)
- Tumor size tracking
- Surgical planning
- Needle specifications
- Medical device dimensions
Why mm in medicine:
- International standard
- Appropriate precision
- Imaging system default
- Research compatibility
- Treatment standardization
When to Use ken
The Ken's primary importance lies in its role as an architectural module:
- Traditional Japanese Architecture: It defines the standard bay (pillar-to-pillar distance) in the ken module system (kenshin system ιη). This dictates the layout and proportions of temples, shrines, traditional houses (minka), teahouses, and castles. Room sizes are often described in terms of tatami mats, whose standard dimensions (historically 1 Ken by 0.5 Ken) are derived from the Ken.
- Construction and Carpentry: Used for planning layouts, cutting timber, and sizing building components like fusuma (sliding doors) and shΕji (screens).
- Real Estate and Land: Room sizes in Japan are often measured by the number of tatami mats they can hold (e.g., a "6-mat room" - ε η³ rokujΕ), which indirectly relates to the Ken. Historically, it was also used for land parcel dimensions.
- Martial Arts: The concept of distance or interval (maai ιεγ) between opponents is crucial and sometimes measured or conceptualized in terms of Ken. The length of certain weapons, like the bΕ (staff), is often around 1 Ken (6 Shaku).
- Traditional Garden Design: Used for establishing proportions and spacing elements within Japanese gardens.
- Cultural and Historical Context: Understanding the Ken is essential for interpreting historical architectural plans, documents, and cultural descriptions of space.
Additional Unit Information
About Millimeter (mm)
How many millimeters are in a centimeter?
There are exactly 10 millimeters (mm) in 1 centimeter (cm).
Conversion:
- 1 cm = 10 mm
- To convert cm to mm: multiply by 10
- To convert mm to cm: divide by 10
Examples:
- 5 cm = 50 mm
- 2.5 cm = 25 mm
- 75 mm = 7.5 cm
Memory aid: "Centi-" means 1/100 meter, "milli-" means 1/1,000 meter, so 10 mm = 1 cm.
Use our cm to mm converter for instant conversions.
How many millimeters are in a meter?
There are exactly 1,000 millimeters (mm) in 1 meter (m).
Conversion:
- 1 m = 1,000 mm
- To convert m to mm: multiply by 1,000
- To convert mm to m: divide by 1,000
Examples:
- 0.5 m = 500 mm
- 1.5 m = 1,500 mm
- 2,750 mm = 2.75 m
Remember: "Milli-" means one-thousandth, so it takes 1,000 mm to make 1 meter.
Convert: mm to meters | meters to mm
What does 'milli' mean in millimeter?
The prefix 'milli-' denotes one-thousandth (1/1,000).
Meaning:
- Comes from Latin "mille" meaning "thousand"
- In metric system: milli- = 10β»Β³ = 1/1,000
- 1 millimeter = 1/1,000 of a meter = 0.001 m
Other "milli-" units:
- Milligram (mg) = 1/1,000 gram
- Milliliter (mL) = 1/1,000 liter
- Millisecond (ms) = 1/1,000 second
- Milliamp (mA) = 1/1,000 ampere
Pattern: Always divide by 1,000 to get the base unit.
How thick is 1 millimeter?
1 millimeter is very thin - about the thickness of:
Common objects:
- Credit card: 0.76 mm (slightly thinner)
- US dime: 1.35 mm (slightly thicker)
- 10 sheets of paper: ~1 mm
- Paperclip wire: ~1 mm diameter
- Mechanical pencil lead (0.7mm): Slightly thinner
Visual comparison:
- Thinner than a US penny (1.55 mm)
- About 1/25th of an inch (0.04 inches)
- 10 millimeters = 1 cm = width of fingernail
To visualize: Look at the edge of a credit card - that's less than 1 mm.
How many mm in an inch?
1 inch = 25.4 millimeters exactly (by international agreement).
This is a defined conversion (not an approximation):
- 1 inch β‘ 25.4 mm (exact)
- 1 mm = 1/25.4 inch β 0.03937 inches
Common conversions:
- 1 inch = 25.4 mm
- 2 inches = 50.8 mm
- 3 inches = 76.2 mm
- 4 inches = 101.6 mm
- 12 inches (1 foot) = 304.8 mm
Reverse examples:
- 10 mm β 0.394 inches
- 25 mm β 0.984 inches (almost 1 inch)
- 50 mm β 1.969 inches (almost 2 inches)
Memory trick: 25 mm is almost 1 inch (close enough for quick estimates).
Use our inch to mm converter for precise conversions.
What is 10mm in real life?
10 millimeters = 1 centimeter - about the width of an adult fingernail.
Common 10mm objects:
- Fingernail width (adult index finger)
- AA battery diameter: 14 mm (close)
- Small marble: ~10-15 mm diameter
- M10 bolt diameter: 10 mm
- Thick cardboard: ~10 mm
Comparisons:
- Just under 0.4 inches (0.394 inches exactly)
- Thickness of 100 sheets of paper
- About 3/8 inch (slightly larger)
In measurements:
- Camera/phone thickness: Often 7-10 mm
- Watch case thickness: Often 10-12 mm
- Pencil diameter: ~7-8 mm (10mm would be thick)
How do you read a metric ruler?
Metric rulers are divided into centimeters (cm) and millimeters (mm):
Reading steps:
- Large numbers: Centimeters (0, 1, 2, 3...)
- Long lines: Each centimeter mark
- Short lines: Millimeters (10 per cm)
- Count: From zero to your measurement point
Example reading:
- Between 3 and 4 cm, at the 7th small line = 3.7 cm or 37 mm
- At the 15th cm mark = 15 cm or 150 mm
Tips:
- 10 small marks = 1 cm
- Each small mark = 1 mm
- Halfway between cm marks = 5 mm
- Read to nearest 0.5 mm for precision
Reporting:
- Small objects: Use mm (e.g., "15 mm")
- Larger objects: Use cm (e.g., "15.5 cm")
- Both are correct, choose clearer one
What tools measure millimeters?
Many tools measure in millimeters:
Hand Tools:
- Metric ruler: Basic measurement to 1 mm
- Metric tape measure: Construction/carpentry
- Caliper: Precision to 0.01 mm (digital/vernier)
- Micrometer: Very precise, to 0.001 mm
- Depth gauge: Measuring depths and heights
Digital Tools:
- Digital caliper: Easy reading, 0.01 mm precision
- Laser distance meter: Millimeter accuracy
- Height gauge: Vertical measurements
- Coordinate measuring machine (CMM): Industrial precision
Specialized Tools:
- Feeler gauge: Thin strips in mm thicknesses
- Thread gauge: Checking thread pitch (mm)
- Bore gauge: Internal diameter measurement
- Pin gauge: Precision hole measurement
Which to use:
- Ruler: General purpose (Β±0.5 mm)
- Caliper: Precision work (Β±0.01 mm)
- Micrometer: Very tight tolerances (Β±0.001 mm)
Is mm smaller than cm?
Yes, millimeters (mm) are smaller than centimeters (cm).
Relationship:
- 1 cm = 10 mm
- 1 mm = 0.1 cm
- Millimeter is 10 times smaller than centimeter
Scale comparison:
- Largest: meter (m)
- Middle: centimeter (cm) = 1/100 m
- Smallest: millimeter (mm) = 1/1,000 m
Visual:
- Width of fingernail: 1 cm = 10 mm
- Thickness of dime: 1.35 mm (can't easily express in cm)
When to use each:
- Use mm: Small, precise measurements (< 100 mm)
- Use cm: Medium measurements (1-100 cm)
- Use m: Large measurements (> 1 meter)
Example:
- Pencil length: 19 cm or 190 mm (19 cm clearer)
- Wire diameter: 2 mm (not 0.2 cm - awkward)
How much rain is 1mm?
1 millimeter of rain means 1 mm depth of water would cover a flat surface if none drained away.
What it means:
- 1 mm rain = 1 liter per square meter of water
- Light drizzle might produce 1-2 mm/hour
- Barely enough to wet the ground thoroughly
Rain intensity scale:
- Trace-1 mm: Very light drizzle
- 1-2 mm: Light rain
- 2-5 mm: Light to moderate rain
- 5-10 mm: Moderate rain
- 10-20 mm: Heavy rain
- 20-50 mm: Very heavy rain
- >50 mm: Extreme rainfall (per hour)
Practical impact:
- 1 mm: Barely wets surfaces
- 10 mm: Significant watering
- 25 mm: Heavy rain event
- 100 mm: Major storm (in 24 hours)
Measurement:
- Rain gauge collects water
- Depth measured in mm
- Standard worldwide for weather reporting
About Ken (ken)
How long is a Ken?
The modern standard Ken is defined as 6 Shaku. Using the standardized kanejaku Shaku (10/33 m):
- 1 Ken = 20/11 meters
- Approximately 1.818 meters
- Approximately 181.8 centimeters
- Approximately 5.965 feet
- Approximately 71.58 inches Historical and regional variations (like the kyΕma) existed, often resulting in slightly different lengths.
How does the Ken relate to the Shaku?
The Ken is a direct multiple of the Shaku:
- 1 Ken = 6 Shaku
Is the Ken related to the Tatami mat?
Yes, very closely. The standard size of a tatami mat was traditionally defined in relation to the Ken, typically 1 Ken long by 0.5 Ken wide (though dimensions varied slightly with regional modules like kyΕma and inakama). Room sizes are often measured by the number of tatami mats they contain.
Is the Ken an SI unit?
No, the Ken is not an SI unit. It is a traditional Japanese unit belonging to the ShakkanhΕ (尺貫ζ³) system. The SI base unit for length is the meter (m).
Is the Ken still used today?
Yes. While the metric system is the official standard in Japan for commerce and science, the Ken remains highly relevant and actively used in:
- Traditional Japanese architecture, design, and construction.
- Carpentry and traditional crafts.
- Real estate descriptions (indirectly via tatami count).
- Martial arts contexts.
- Cultural and historical studies.
- Traditional garden design.
Conversion Table: Millimeter to Ken
| Millimeter (mm) | Ken (ken) |
|---|---|
| 0.5 | 0 |
| 1 | 0.001 |
| 1.5 | 0.001 |
| 2 | 0.001 |
| 5 | 0.003 |
| 10 | 0.006 |
| 25 | 0.014 |
| 50 | 0.028 |
| 100 | 0.055 |
| 250 | 0.138 |
| 500 | 0.275 |
| 1,000 | 0.55 |
People Also Ask
How do I convert Millimeter to Ken?
To convert Millimeter to Ken, enter the value in Millimeter in the calculator above. The conversion will happen automatically. Use our free online converter for instant and accurate results. You can also visit our length converter page to convert between other units in this category.
Learn more βWhat is the conversion factor from Millimeter to Ken?
The conversion factor depends on the specific relationship between Millimeter and Ken. You can find the exact conversion formula and factor on this page. Our calculator handles all calculations automatically. See the conversion table above for common values.
Can I convert Ken back to Millimeter?
Yes! You can easily convert Ken back to Millimeter by using the swap button (β) in the calculator above, or by visiting our Ken to Millimeter converter page. You can also explore other length conversions on our category page.
Learn more βWhat are common uses for Millimeter and Ken?
Millimeter and Ken are both standard units used in length measurements. They are commonly used in various applications including engineering, construction, cooking, and scientific research. Browse our length converter for more conversion options.
For more length conversion questions, visit our FAQ page or explore our conversion guides.
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Other Length Units and Conversions
Explore other length units and their conversion options:
- Meter (m) β’ Millimeter to Meter
- Kilometer (km) β’ Millimeter to Kilometer
- Hectometer (hm) β’ Millimeter to Hectometer
- Decimeter (dm) β’ Millimeter to Decimeter
- Centimeter (cm) β’ Millimeter to Centimeter
- Inch (in) β’ Millimeter to Inch
- Foot (ft) β’ Millimeter to Foot
- Yard (yd) β’ Millimeter to Yard
- Mile (mi) β’ Millimeter to Mile
- Nautical Mile (NM) β’ Millimeter to Nautical Mile
Verified Against Authority Standards
All conversion formulas have been verified against international standards and authoritative sources to ensure maximum accuracy and reliability.
National Institute of Standards and Technology β Official US standards for length measurements
Bureau International des Poids et Mesures β International System of Units official documentation
Last verified: February 19, 2026